Browse Topic: Oxygen

Items (1,275)
Purified nickel and a large number of MgTi2 / NiO2 catalysts with various MgTi2 loadings were produced using the traditional incipient wetness method. X-ray crystallography and Fourier-transform infrared spectroscopy were used to examine the catalysts. To understand the material's microstructure better, the researchers investigated oxygen adsorption at 90K. The amine titration method was used to investigate the acidic characteristics of these catalysts. In a study on cumene cracking, these catalysts were employed. The catalyst was found to be amorphous up to a loading of 12 weight percent MgTi2, but at higher loadings, crystalline MgTi2 phase formed on an amorphous silica substrate. When NiO2 is doped with more MgTi2, there are significant differences in the structure, surface acidity, and catalytic activity of the catalysts. Catalysts with a higher MgTi2 loading are noticeably more acidic than those with a lower MgTi2 loading. A correlation between the amount of cracking activity and
Ashok Kumar, B.Dhiyaneswaran, J.Selvaraj, MalathiPradeepkumar, M.Shajeeth, S.
I’m guessing that when you think about applications for AI, physical fitness is not the first thing that comes to mind. But it is actually one of the more common applications. The most popular fitness sensors use AI to keep track of how many steps you’ve taken, track your progress, and integrate that with health information like heartrate or even blood oxygen level. But AI can do much more than that
Currently, existing civil aviation standards address the design and certification of oxygen dispensing devices that utilize oxygen sources supplying at least 99.5% oxygen. This Aerospace Information Report discusses issues relating to the use in the passenger cabin of oxygen enriched breathing gas mixtures having an oxygen content of less than 99.5% and describes one method of showing that passenger oxygen dispensing devices provide suitable hypoxia protection when used with such mixtures
A-10 Aircraft Oxygen Equipment Committee
This SAE Aerospace Standard (AS) defines the overall requirements applicable to oxygen flow indication as required by Airworthiness Requirements of CS/FAR 25.1449 to show that oxygen is being delivered to the dispensing equipment. Requirements of this document shall be applicable to any type of oxygen system technology and encompass “traditional” pneumatic devices, as well electric/electronic indication
A-10 Aircraft Oxygen Equipment Committee
This study mainly focuses on the blending of Alumina and Titanium oxide nanoparticles (NP’s) in Spirulina biodiesel blends (SB20) to estimate the influence of engine (combustion, performance and emission) parameters of a diesel engine. The characterization of Al2O3 and TiO2 NP’s like SEM were reported. By using various fuel samples such as Diesel, SB20, SB20+40 ppm AO, SB20+80 ppm AO, SB20+40 ppm TO and SB20+80 ppm TO, the engine tests on the diesel engine were conducted at various load conditions. The BTE for SB20+80 ppm AO were enhanced by 12.35% and 8.4 % compared to the SB20 fuel and SB20+40 ppm AO fuel samples. The combustion parameters were improved for the NP’s as additives (Al2O3 and TiO2) fuels than the SB20 fuel sample because NP’s contain oxygen content. The parameters of engine exhaust emissions such as HC, CO and smoke are drastically diminished for the SB20+40 ppm AO, SB20+80 ppm AO, SB20+40 ppm TO and SB20+80 ppm TO fuels compared to the SB20 fuel. A marginal improvement
Anchupogu, PraveenKrupakaran, R LGanipineni, Jamuna RaniPetla, Ratna Kamala
Ammonia has attracted the attention of a growing number of researchers in recent years. However, some properties of ammonia (e.g., low laminar burning velocity, high ignition energy, etc.) inhibit its direct application in engines. Several routes have been proposed to overcome these problems, such as oxygen enrichment, partial fuel cracking strategy and co-combustion with more reactive fuels. Improving the reactivity of ammonia from the oxidizer side is also practical. Ozone is a highly reactive oxidizer which can be easily and rapidly generated through electrical plasma and is an effective promoter applicable for a variety of fuels. The dissociation reaction of ozone increases the concentration of reactive radicals and promotes chain-propagating reactions. Thus, obtaining accurate rate constants of reactions related to ozone is necessary, especially at elevated to high pressure range which is closer to engine-relevant conditions. In present work, rate constants of ozone dissociation
Zhang, ZhenyingnanLi, AngLi, ZhuohangZhu, LeiHuang, Zhen
Although progress has recently been made to characterise the transition of microscopic liquid fuel droplets from classical evaporation to a diffusive mixing regime, still little is known about the transition from one to the other under reactive conditions. The lack of experimental data for microscopic droplets at realistic operating conditions impedes the development of phenomenological and numerical models for droplet mixing, ignition, combustion and soot formation. In order to address this issue we performed systematic measurements using high- speed long-distance microscopy, for n-dodecane into gas at elevated temperatures (from 750 to 1,600 K) and pressures up to 13 MPa. We describe these high- speed visualizations at the microscopic level, including the time evolution of the liquid droplets, reaction wave, and soot distribution. Our measurements show that these parameters are influenced by the operating conditions (gas pressure, gas temperature, oxygen content) as well as the
Crua, CyrilManin, JulienSkeen, ScottPickett, Lyle M
Diesel engines operated at high altitudes would experience performance degradation due to the fuel-air amount mismatch, resulting in combustion deterioration. Technologies that supplement oxygen concentration, such as intake oxygen enrichment, turbocharging and the addition of oxygenated fuel additives, can help restore performance at high altitudes, but each has its own limitations Operating diesel engines at high altitudes still generates extremely lean fuel-air mixtures, making the improved utilization of excess air the most economically efficient approach to optimize engine performance under such conditions. The objective of this paper is to investigate the effects of injector nozzle-hole numbers on diesel engines operated at high altitudes, a topic that has been limitedly discussed in existing literature, with the aim of enhancing understanding regarding the potential of this cost-effective approach and aiding in the design of a cooperative approach between oxygen concentration
Zhao, JunliangYang, RuomiaoYan, YuchaoOu, JuanLiu, ZhentaoLiu, Jinlong
This document is intended to give general instructions and directions for personnel performing maintenance and modification work on Oxygen Systems
A-10 Aircraft Oxygen Equipment Committee
This standard covers regulators of the following types: Type I - Automatic Continuous Flow Type II - Adjustable Continuous Flow Type III - Pre-Set Continuous Flow Class A - Cylinder Mounted Class B - Line Mounted
A-10 Aircraft Oxygen Equipment Committee
This SAE Aerospace Standard (AS) is intended to apply to those oxygen regulators which supply gaseous oxygen at breathing pressures to meet physiological requirements of aircraft flight crew members. It defines the minimum performance requirements and testing for aircraft demand type breathing oxygen regulators
A-10 Aircraft Oxygen Equipment Committee
This document defines the minimum degree of purity and maximum levels of certain deleterious impurities allowable for aviator's breathing oxygen at the point of manufacture or generation. It covers gaseous, liquid, and chemically generated oxygen, and oxygen supplied by in situ concentration and in situ electrolysis. Different limits are established for oxygen from different sources, in recognition of differences in the ways the oxygen is stored, dispensed, and utilized, taking into account the safety of the user. These limits are not intended to specifically reflect upon the relative capabilities or merits of various technologies. Procurement documents may specify more stringent limits, where required for specific applications. Medical oxygen is not covered by this standard. In the United States, medical oxygen is a prescription drug and complies with the United States Pharmacopoeia (USP). In Europe, medical oxygen specification compiles with the European Pharmacopoeia monograph (Ph
A-10 Aircraft Oxygen Equipment Committee
This specification covers a stable, noncorrosive, water-soluble, highly-penetrating, fluorescent solution which may, but need not, be diluted with an appropriate amount of water for use
AMS K Non Destructive Methods and Processes Committee
With the ever-increasing demand for sustainable energy, alcohol fuels have garnered interest for use in heavy duty engines. The significant infrastructure for ethanol production and blending of ethanol with gasoline make these fuels/fuel blends desirable candidates. However, development of heavy duty engine technology that is capable of burning alcohol fuels while retaining the advantages of traditional diesel combustion requires an improved understanding of the soot formation for these fuels under conditions relevant to mixing-controlled combustion. This work uses an extinction diagnostic to study the sooting tendency of ethanol and gasoline/ethanol blends ranging from E10 to E98 during ignition in a homogeneous environment. Experiments were conducted in a rapid compression machine (RCM) for compressed conditions of 20 ± 1 bar and an approximately constant temperature (± 10K) which was unique for each fuel. For a given soot volume fraction, a linear relationship was observed between
Gross, JosephChowdhury, MusharratDempsey, AdamAllen, Casey
A new kind of solar panel, developed at the University of Michigan, has achieved 9 percent efficiency in converting water into hydrogen and oxygen — mimicking a crucial step in natural photosynthesis. Outdoors, it represents a major leap in the technology, nearly 10 times more efficient than solar water-splitting experiments of its kind
The scope of this document is related to the particular needs of oxygen equipment with regards to packaging and transportation. The document provides guidance for handling chemical, gaseous and liquid oxygen equipment. It summarizes national and international regulations to be taken into account for transportation on land, sea and air and provides information on classification of hazardous material. The aim of this document is to summarize information on packaging and transportation of oxygen equipment. Statements and references to regulations cited herein are for information only and should not be considered as interpretation of a law. Processes to maintain cleanliness of components and subassemblies during processing and assembly or storage of work-in-progress are outside the scope of this document. Guidance on this can be obtained from ARP1176. Rules for transportation and shipment do not cover oxygen equipment installed in an interior monument, e.g., galley unit or in a fuselage
A-10 Aircraft Oxygen Equipment Committee
Vulcan XC 72R was modified in two different ways (i.g., treated by the NH3 gas or urea). The impact of modification strategies was analyzed by correlating the structure and chemical properties of carbons with the catalytic activity and stability of corresponding catalysts. Pt clusters are homogeneously distributed through the nitrogen-doped carbon support. Electronegative nitrogen atoms create positive charge on neighbor carbon atoms. The increased interaction between the carbon support and PtCl62- restrains the nucleation of platinum. N2 adsorption-desorption results indicated that abundant of micropores were created and the proportion of micropores obviously increased from 2.8 % to 11.4 %. XPS measurement distinguished different N functionalities. Pyridinic-N and pyrrolic-N were introduced on the surface of carbon support. Pt/NC catalyst exhibits the best ORR performance among all as-prepared catalysts in 0.1 M KOH solution. Moreover, the stability of Pt/NC is superior with minor
Wang, QianLiu, MingtaoZhou, LuLi, Yunqi
This specification covers a premium aircraft-quality alloy steel in the form of bars and forgings 199 square inches (1284 cm2) and under in cross section, and forging stock of any size
AMS E Carbon and Low Alloy Steels Committee
This report presents, paraphrased in tabular format, an overview of the Federal Aviation Regulations (FAR) for aircraft oxygen systems. It is intended as a ready reference for those considering the use of oxygen in aircraft and those wishing to familiarize themselves with the systems requirements for existing aircraft. This document is not intended to replace the oxygen related FAR but rather to index them in some order. For detailed information, the user is referred to the current issue of the relevant FAR paragraph referenced in this report
A-10 Aircraft Oxygen Equipment Committee
A three-way automotive catalyst's ability to store oxygen is still a crucial performance metric for modern day catalyst applications. With more stringent emissions legalisation, the oxygen storage capacity (OSC) within a catalyst can assist with converting different harmful exhaust gases such as CO, THC and NOx under transient operating conditions. Additionally, OSC is currently the only onboard catalyst performance metric recorded during a vehicle's useful life. Catalyst performance is correlated to this OSC measurement. OSC in three-way automotive catalysts can be split into two main OSC types. "Latent" OSC deep within the washcoat and "dynamic" OSC on the surface of the catalyst washcoat. Dynamic OSC is more commonly applied in the evaluation of useful OSC of the catalyst during practical operation
Mc Grane, LiamDouglas, RoyElliott, MatthewIrwin, KurtisWoods, AndrewPedlow, Andrew
The intended upper bound of this specification is that the particle size distribution (PSD) of powders supplied shall be <60 mesh (250 μm) and that no powder (0.0 wt%) greater than 40 mesh (425 μm) is allowed
AMS AM Additive Manufacturing Metals
This specification covers a premium aircraft-quality alloy steel in the form of bars, forgings 100 square inches (645 cm2) and under in cross-sectional area and forging stock of any size
AMS E Carbon and Low Alloy Steels Committee
This specification covers a premium aircraft-quality alloy steel in the form of bars and forgings 189 in2 (1219 cm2) and under in cross-sectional area and forging stock of any size
AMS E Carbon and Low Alloy Steels Committee
This specification covers connector and cable accessory heat shrinkable, electrical insulating, molded components fabricated from various polymer based compositions. These components are intended for use as connector and cable accessory components to provide strain relief, electrical insulation, and environmental sealing
AE-8C1 Connectors Committee
In this experimental study, an attempt is made to enhance the performance characteristics of diesel fuel with two different natural additives (NA). Borassus Flabelifer (NB1) and Oryza Sativa straws (NB2) were chosen as natural additives. The selected natural additives were milled for 150 hours using a planetary ball mill and their particle sizes ranging from 120 to 125 nm. The milled natural additives were doped into neat diesel using a magnetic stirrer followed by ultrasonication and their stability was ascertained. The presence of high carbon and oxygen content was noted on EDS results of milled powder. The properties of fuel were analyzed as per ASTM standards and it was observed that there was a marginal decrease in calorific value, flash point, and fire point of the fuel. Performance analysis of the fuel was carried out in a diesel engine at different load conditions and it was observed that brake thermal efficiency reduced by 1.73 % and 1.24 % for NB1 and NB2 doped diesel
Velusamy, RajaAnnamalai, Suresh BabuSwaminathan, Mangudi RangawamyPeriyana Pillai, HariharanGanapathy, SakthinathanRadhakrishnan PhD, VigneshKumar, Premkumar
This aerospace standard (AS) defines the requirements of portable protective breathing equipment for use during smoke/fire conditions on board an aircraft
A-10 Aircraft Oxygen Equipment Committee
This specification covers a corrosion and heat-resistant steel alloy in the form of pre-alloyed powder
AMS AM Additive Manufacturing Metals
Engineers have created a tiny wireless implant that can provide real-time measurements of tissue oxygen levels deep underneath the skin. The device, which is smaller than the average ladybug and powered by ultrasound waves, paves the way for the creation of a variety of miniaturized sensors that could track key biochemical markers in the body such as pH or carbon dioxide. These sensors could one day provide doctors with minimally invasive methods for monitoring the biochemistry inside functioning organs and tissues
Activation loss, mass transfer loss and ohmic loss are the three main voltage losses of the polymer electrolyte membrane fuel cell. While the former two types are relevant to concentration of oxygen in catalyst layer and the later one is associated with the water content in membrane. Distributions of water content and oxygen in a single cell are inconsistent which cause that current densities in each segment of the single cell are different. For the dry inlet gas, the water in the segments near the gas inlet channel will be carried to the segments near the gas outlet channel, which causes high ohmic loss of the segments near the gas inlet channel. In this work, a transfer non-isothermal quasi-three-dimensional model is developed to investigate inconsistency of current densities. Comprehensive physical and chemical phenomena inside the cell are included, especially the mass transfer of hydrogen, oxygen, vapor and liquid water in gas channels, gas diffusion layer and catalyst layer and
Wang, XuhuiLu, YikangZhang, BaitaoXu, Sichuan
The argon power cycle engine, which uses hydrogen as fuel, oxygen as oxidant, and argon other than nitrogen as the working fluid, is considered as a novel concept of zero-emission and high-efficiency system. Due to the extremely high in-cylinder temperature caused by the lower specific heat capacity of argon, the compression ratio of spark-ignition argon power cycle engine is limited by preignition or super-knock. Compression-ignition with direct-injection is one of the potential methods to overcome this challenge. Therefore, a detailed flammability limit of H2 under Ar-O2 atmosphere is essential for better understanding of stable autoignition in compression-ignition argon power cycle engines. In this study, with the HCCI code of CHEMKIN, the influence of argon dilution ratio, compression ratio, excess oxygen ratio, and engine speed on engine performance indicators including indicated thermal efficiency, CA10 (crank angle at 10% of total heat release), CA50, CA90-10, and in-cylinder
Xie, KaienDeng, JunJin, ShaoyeLi, Liguang
Researchers have integrated water purification technology into a new proof-of-concept design for a sea water electrolyzer that uses an electric current to split apart the hydrogen and oxygen in water molecules. This new method for “sea water splitting” could make it easier to turn wind and solar energy into a storable and portable fuel
AIR5933 provides an overview of contemporary technologies (i.e., sensors) that measure the proportion of oxygen in a gas. The use of these sensors in the aerospace environment, with its special constraints, is discussed and papers/reports with detailed information are summarized and referenced. The sensors are divided into expendable and non-expendable sensors. Expendable sensors are based on electrochemical properties, whereas non-expendable sensors rely on paramagnetic, photo-acoustic, electromagnetic, and laser spectroscopy properties
A-10 Aircraft Oxygen Equipment Committee
The intended upper bound of this specification is that the particle size distribution (PSD) of powders supplied shall be <60 mesh (250 µm) and that no powder (0.0 wt%) greater than 40 mesh (425 µm) is allowed
AMS AM Additive Manufacturing Metals
The oxidation of raw materials, such as phenolic resin, in the pad during the braking depends on the temperature but also on the oxygen diffusion capability through the pad. Determination of oxygen diffusion is a key point in knowing how deep from the surface tribochemistry can take place. The diffusion of oxygen through the pad is a drawback because it induces the matrix decomposition that contributes to intra-stop CoF instability and consequently worsens NVH. This study is focused on determining the oxygen diffusion through brake pads using oxidized iron sulphide particles as indicator parameter. Iron sulphide has a rough microstructure when it becomes oxide that can be recognized easily, making it a good marker. The oxygen diffusion was determined through the pad characterization, after SAE J2522 and J2707 tests, with SEM and EPMA/WDS techniques. The results show that tribochemistry also takes place beneath the PAD surface during braking due to the oxygen presence and the high
Macías, GabrielaLorenzana, CarlosFernandez, Javier
In order to keep the coefficient of friction stable, some additives such as metal sulphides, are included in the brake pads formulation. Previous work from RIMSA has shown that oxidation temperature range of the metal sulphides can be one of the key properties to explain their contribution to the performance and wear of a PAD. This new work is a step forward in the interpretation of the mechanism of sulphides as chemically active additives in the brake pads. Phenolic resin is the matrix of the brake pads and starts to decompose around 300 °C in presence of oxygen and temperature. In order to establish a connection on between sulphide oxidation and phenolic resin degradation, several studies based on heat treatment of blends of different metal sulphides (Iron sulphide, Tin sulphide and Composite sulphide) with phenolic resin have been done. Then the material evolution was studied with techniques such as TGA-DSC, XRD, IR and SEM-EDS. The results obtained confirm that there is an
Macías, GabrielaLorenzana, CarlosFernandez, Javier
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